I turned on Google Search History because I figured it might be useful to have this data available at some point in the future. However the implementation of the feature has be about ready to turn it off.
I was rather accustomed to doing a search for something, right clicking on the result I wanted and copying the URL (to use in a blog post, etc.). With Search History enabled, all of the URLs in the search results are google.com redirect URLs. This means I have to click through, wait for the site to load, put focus in the location bar and copy to get what I used to get from my right click in the results list.
It doesn’t have to be this way either, a simple JS action on the real URLs (doesn’t Google Analytics already do this) would give Google the same ability to capture the “click” data without having to modify the URLs. Heck, they might do this already on normal search result pages.
I obviously haven’t looked into this in depth, this is just my experience so far. Feel free to make corrections and suggestions in the comments.